Brain circuits mediating the orexigenic action of peripheral ghrelin: narrow gates for a vast kingdom.

AGUSTINA CABRAL; PABLO N. DE FRANCESCO; MARIO PERELLÓ

Frontiers in Endocrinology

endocrinology editorial

Año: 2015

1664-2392

The nervous and endocrine systems act together to regulate all physiological processes essential for the body homeosta- sis control. Given the strict communica- tion restrictions that the brain?blood bar- rier (BBB) imposes, the interplay between these two systems requires a variety of deli- cate anatomical interfaces and physiolog- ical mechanisms that guarantee the pre- cise function of the neuroendocrine system as a whole. The study of the mechanisms by which hormones act in the brain in order to regulate specific neuronal popu- lations is a research topic rather neglected. Our group studies the neuronal circuitries and molecular mechanisms by which the stomach-produced hormone ghrelin regu- lates appetite and other physiological func- tions. A clear notion of the brain targets of peripheral ghrelin is essential for the comprehensive understanding of the phys- iological role of this hormone. Ghrelin is called ?the hunger hormone? since it is the only known orexigenic peptide hormone. The target for ghrelin orexigenic actions is the brain, which contains a variety of ghrelin-responsive nuclei; however, several evidences suggest that the accessibility of peripheral ghrelin to the brain is strik- ingly low. Here, we briefly summarize the current knowledge in this topic and dis- cuss this intriguing neuroendocrinological issue.